Spatial differences in reproduction of capelin (Mallotus villosus socialis) in the coastal waters of Sakhalin

Abstract

Capelin spawn in all main coastal areas of Sakhalin Island except the Amur estuary (i.e. in the northwest, southwest, and northeast of the Island, including Aniva and Terpeniya Bays). In all those areas, spawning stocks of capelin exhibit significant differences in population parameters (size–age composition, growth, fecundity), periods and intensity of spawning, and rates of egg mortality. The areas are distinguished also by the parameters of the spawning areas, oceanographic conditions, zooplankton biomass, numbers of pelagic and demersal fish species, and abundance of planktivorous fish and seabirds. Conditions are clearly best for reproduction and growth of capelin off northwestern Sakhalin Island.